Homogeneous composition and process for making the same



Patented Jan. 22, 1935 UNITED STATES PATENT OFFICE HOMOGENEOUS cfil ifiisl'iloN AND PltOC- V I .ESS' FOR MAKING THE SAME Leo I. Dana and Carl W.Georgi, Buffalo, N. Y..-

assignors to Carbide and Carbon Chemical:

Corporation, a corporation of New York No Drawing.

2 Claims.

The use of various alcohols as freezing point depressants for liquidmedia is well known, and the low freezing compositions containingalcohols have been the subject of many modifications 5 and improvements.Alcohols proposed for use in anti-freeze compositions include all of thesaturated aliphatic hydroxy compounds, such as the monohydroxy alcohols,methyl, ethyl, isopropyl and propyl alcohols; the alkoxy alcohols, suchas betaethoxy ethyl alcohol and betabutoxy ethyl alcohol; and thepolyhydroxy alcohols, such as ethylene and diethylene glycol, propyleneglycol, alkylene glycols generally of the 1, 2 series, and glycerol. Asused in this specification and the appended claims, the term alcoholwill be understood to include all of the above compounds.

Among the improvements proposed for alcoholic anti-freeze solutions maybe listed the addition of various agents to lessen the tendency of suchsolutions to become corrosive to iron and other metals. Corrosioninhibitors for this purpose may be those disclosed in applications forpatent Serial No. 377,620, filed July 11, 1929, Serial No. 495,302,filed November 11, 1930, and Serial No. 607,507, filed April 25, 1932,by H. L. Cox; those disclosed in Patent No. 1,433,226 issued October 24,1922 to C. W. Porter; or other -corrosion inhibitors known in the artincluding the aromatic primary, secondary, and tertiary diamines, suchas m-toluylene diamine; aldehyde-amine condensation products, such asthe product formed by condensing butyraldehyde and aniline in the ratioof 2:1; polyalkylene imines and polyamines; heterocyclic nitrogenousbases, such as pyrrolidine and piperidine; and nitrogenous bases of thealiphatic series other than those disclosed or mentioned above. Othermodifying additions may include agents to combat the foam-formingproperties of the compositions, as

40 shown by application for patent Serial No.

' 50,7,045, filed January 6, 1931, by L. J. Clapsadle;

substances to decrease the tendency of compositions to escape from thesystem in which it is confined, as disclosed by application for patent 5Serial No. 507,047, filed January 6, 1931, by H. L.

\ Cox; and other additions for various specific purposes.

All of these proposals have resulted in generally x improvedcompositions which have wide applica- 59 tion in protecting liquid mediafrom congealing at low temperatures, but certain of the improvementshave simultaneously brought about difliculties not present in theunmodified compositions, and not heretofore overcome. For exll ample, ithas been found that an improved com- Application November .12, 192112,:Serial No. 642,456

position, which with water forms an excellent medium for the transfer ofheat or pressure, may be formed by adding an oleaginous materialcontaining free fatty acid together with a corrosion inhibitor and asmall quantity of an alkaline earth metal salt which yieldssubstantially neutral aqueous solutions to an alcohol. An example ofsuch composition may comprise about 0.50% to 1.50%by volume of an animalor vegetable oil containing at least about 5% to 10% of free 10 fattyacid, about 0.25% to 0.75% by volume of hydroxyalkylamine or asufiicient quantity to produce a basicity in the final compositionrepresented by a pH value of not less than about 8, and from about 0.01%to 0.1% by weight of the alkaline earth metal salt, with or without anadditional quantity of a mineral oil not exceeding the amount ofvegetable or animal oil in the composition, and the balance beingprincipally an alcohol. Within the ranges given a preferredcomposition-may be formed of about 1.0% by volume lard oil containing10% to 15% of free fatty acid, about 0.5% by volume of crudetriethanolamine (i. e. containing monoethanolamine and diethanolamine aswell as triethanolaminc), about 0.2% by volume of mineral oil, and about0.02% by weight of calcium acetate, the balance of the mixtureconsisting principally of ethylene glycol. This preferred composition isa particularly useful non-foaming, non-corrosive freezing pointdepressant for use in automobile radiators, and it has little or notendency to escape from the radiator through minor crevices. Thecomposition does possess certain disadvantages. For instance themodifying additions separate from the ethylene glycol as an immiscibleliquid phase, and when the modified composition is transported ordistributed in relatively large containers, such as drums or tank cars,it is practically impossible to withdraw portions of the compositionwhich will have the desired composition without providing for expensiveand cumbersome mechanical agitation at the time of each withdrawal.Also, if the composition is provided in small unit containers difflcultymay be encountered in pouring out the composition since, under certainconditions, the separated oleaginous layermay congeal and act as a sealor partial seal. Ordinary mixing or agitation provides but a temporaryremedy for the difliculty, and consequently must be repeated each timeit is desired to have the composition even approximately homogeneous,since the two immiscible phases separate more or less immediately aftermixing.

The objects of our invention are to avoid as far as possible theforegoing disadvantages presented by compositions of the classdescribed, and to provide an economical and eflicient process for makingsubstantially homogeneous and permanently stable compositions from thosecompositions described which ordinarily possess a plurality ofimmiscible liquid phases. Another object is to provide a substantiallyhomogeneous and permanently stable composition useful as a freezingpoint depressant for liquid media.

We have discovered that the objects of our invention may be attained,and that desirable compositions of the class described may be producedin an entirely novel form which is substantially homogeneous and which,for all practical purposes, remains permanently stable. The process ofour invention broadly comprises making a substantially homogeneouspermanently stable liquid composition from a plurality of immiscibleliquid phases, one of which contains an alcohol and constitutes apredominating proportion of the total, another of which comprisesoleaginous material, and at least one of the phases containing acorrosion inhibitor of the organic base type herein described. We makethe new homogeneous composition by adding to the immiscible liquidphases in admixture an agent for dispersing the phases with each other,or one within another, and thereafter subjecting the immiscible liquidphases together with the dispersant to a mechanical homogenizing action.The product of our process is a liquid which will not separate orstratify into distinct phases upon standing,-

and which, for all practical purposes, may be considered, a singlehomogeneous liquid phase.

which is permanently stable. It is probably formed of one or more of theoriginal separate phases finely divided and dispersed in another of thephases. The continuous and dispersed phases may be either or any of theoriginal immiscible phases, since which of the immiscible liquid isexternal and which is internal in the final com-.

position is 01m importance for the purpose of our invention;

The dispersing agent may be any known surface tension depressant whichdoes not possess properties which counteract or offset the advantageousproperties provided by the other constituents of the composition.Dispersants may be used which also perform another function in thecomposition. For example oleaginous material containing free i'attyacid,such as lard oil, may be saponified or partly saponified with an organicbase, such as a hydroxyalkylamine or other amine, and this combinationwill serve both as a corrosion inhibitor and dispersing agent. Otherdispersing agents may be glycerol, poly ycerol, glycol or poly glycolfatty acid esters, sulfonated fatty acids, naphthalenes or oils whichare substantially neutral; sodium, potassium or ammonium soaps; soapsmade from organic amino bases, and fatty acids; gum tragacanth, gumArabic, and the like. We have also found that small amounts ofpolyethylene glycol monoalkyl ethers, such as diethylene glycolmonobutyl ether, assist in stabilizing the homogenized composition.

The treatment of our invention may be accomplished by any suitablemechanical homogenizing means. For example, one of the various knowntypes of colloid mills may be employed of the disc attrition, concentricring or cone, beater or jetand-cone type. Other equivalent mechanicalmeans for producing violent agitation of the immiscible liquids which iscapable of effecting fine subdivision of the liquids in intimate contactwith each other may be used.

The invention will be illustrated by the following specific example:

A composition containing 1.1% by volume of lard oil (containing about10% to 15% of free fatty acid), 0.18% by volume of straight distilled,naphthenic base mineral oil having a viscosity of about 200 secondsSaybolt'at 100 F., and a pour test of below F., 0.55% by volume of crudetriethanolamine (about 75% to 80% triethanolamine, about 15% to 20%diethanolamine, and about monoethanolamine)' and about 0.02% by weightof calcium acetate, the balance being principally ethylene glycol, wasprepared. This composition as made exhibited two liquid phases whichwere immiscible. The composition was then passed through a colloid millcomprising fluted concentric rings having a clearance between them of0.003 to 0.004 inches, and one of which was being driven so that a.speed of approximately 9,000 feet per minute was maintained at theperiphery of the rings. The composition after being treated as describedapparently contained the oleaginous material and hydroxyalkylaminepermanently dispersed in a physical state of fine subdivision in theethylene glycol, and remained stable after standing for nine weeks, and

- at the end of this period showed no tendency to separate into layers.By way of comparison, the same composition, after thorough mechanicalagitation of the components separated almost completely into two layersafter standing 1 to 2 hours. If the process of our invention isconducted by treating the immiscible liquids in a colloid mill, weprefer to provide clearances between the attriting or beating elementswhich are of the order of about 0.002 to about 0.10 inches, and toprovide agitation which is equivalent to peripheral speeds of about7,000 to about 15,000 feet per minute in those devices having circularmotion. In general, the composition may be composed of analcohol-containing phase constituting at least 95% of the total and maycontain up to about 3.0 or 4.0% by volume of oleaginous materialcontaining at least 5% of free fatty acid. The oleaginous material maybe an organic oil, such as an animal or vegetable oil, or a mixture ofan organic oil with amineral oil. Examples of suitable materials arelard oil, sperm oil, soya bean oil, cotton seed oil and corn oil.Commercially pure fatty acids may be substituted for the above fattyoils. For example, stearic, oleic or linoleic acids may be used.Naphthenic base mineral oils are preferred, and we prefer to use mineraloils of relatively low pour point. The mineral oil may be omittedentirely, and in any case the oleaginous material, whatever its nature,should contain at least 5% of free fatty acids. v

The corrosion inhibitor should be added in sufficient quantity toproduce an alkalinity in the final composition not less than thatrepresented by a pH value of about 8. At the same time the alkalinity ofthe composition should not be allowed to increase beyond thatrepresented by a pH value of about 11, since between the limits of about8 and about 11, the compositions are substantially non-corrosive tobrass, copper, solder and aluminum, as well as to iron, and relatedmetals. In the event that the organic base used as the corrosioninhibitor produces an alkalinity in the final composition greater thanthat represented by a pH value of about 11, the composition may bebuffered by producing a salt of the corrosion inhibitor in thecomposition. for example, the organic base may be partially neutralizedby an acid such as phosphoric, tartaric, acetic, oleic or otherrelatively weak inorganic or organic acid, thus enabling the productionand maintenance of a pH value in the final composition within thepreferred limits. 1

We prefer to include an alkaline earth. metal salt for the purpose ofreducing the tendency of aqueous solutions of the compositions to foamexcessively. The proportion of the alkaline earth metal salt in thecomposition may be between about 0.01 and about 0.1% by weight, about0.02% by weight of calcium acetate being preferred. Those salts ofalkaline earth metals which are water soluble and which producesubstantially neutral aqueous solutions are preferred in order thatundue acidity or alkalinity will not be produced by hydrolysis of thesalt used. I

If hydroxyalkylamines are employed as th corrosion inhibitors, theproportion of oleaginous material containing free fatty acid to thehydroxyalkylamine should be from about .1:1 to about 2:5:1' by volume.Hydroxyalkylamines.

such as the'ethanolamines and the isom'op ol or propanolamines, are wellsuited for use in the new compositions. I t

We claim:--

1. A substantially homogeneous permanently stable liquid compositioncomprising ethylene glycol constituting at least about 95% of the total,an oleaginous material containing lard oil which contains about 10% to15% of free fatty acid together with ethanolamines, the ratio of thequantity of said lard oil to the quantity of said ethanolamines beingfrom about 1:1 to about 2:5:1.

2. A substantially homogeneous permanently stable liquid compositioncomprising ethylene glycol, about 1.0% by volume of lard oilcontainingabout. 10% to 15% of free fatty acid, about 0.2% by volume of mineral011, about 0.5% by volume of a mixture of-ethanolamines and about 0.02%by weight of calcium acetate, the quantity ofethylene glycolconstituting substantially the 20 balance of thecomposition.

LEO I. DANA. CARI-i W. GEORGI.

